A large-diameter continuous ball catcher at the wellhead and its control method

Abstract

The present invention provides a wellhead large-drift diameter continuous ball catcher, comprising a cylindrical pipe section. A wellhead pipeline is connected to the right side of the pipe section. The pipe section tilts downwards by 10 to 15 degrees in a vertical direction of the wellhead pipeline. A safety plug valve, an isolating plug valve and a ball collecting plug valve are orderly disposed on the pipe section from right to left. A screen pipe is disposed within the pipe section between the safety plug valve and the isolating plug valve, and a plurality of overflowing holes are formed in the surface of the screen pipe. A left side of the ball collecting plug valve is connected to a discharge pipeline. An open flow pipeline is connected to the pipe section in the middle of the screen pipe. The wellhead large-drift diameter continuous ball catcher overcomes the defects in the prior art, and is reliable in principle, and simple in structure; the ball catching method is feasible; continuous and efficient tripping ball collection can be achieved, and the safety production requirements of oil and gas fields are met; and powerful guarantee is provided for smooth construction of multi-stage ball sealer staged fracturing.

Description

Technical field [0001] The invention relates to a drilling device, in particular to a wellhead continuous ball catcher with a large diameter and a control method thereof. Background technique [0002] Many domestic oil and gas reservoirs are characterized by the development of multi-layer systems. Practice has shown that multi-layer production can effectively play the contribution of each pay zone to increase single well production. Multi-layer partial pressure has become the key to this type of oil and gas reservoir to increase single well production. [0003] Multi-stage ball-throwing staged fracturing technology is a common technique for multi-layer partial pressure. The technology is to open the sliding sleeve of the closed fracturing section by putting in the holding ball of the corresponding size, and the holding ball and the sliding sleeve ball seat slide downward And plug the fractured interval. The pressure holding ball used to open the sliding sleeve is an important tool...

AI Technical Summary

Problems solved by technology

[0005] (1) Installed in the wellhead or horizontally connected to the side of the wellhead, when the pressure-holding ball is discharged, it is easy to fall into the well again due to impact, resulting in failure to catch the ball and reducing the ball-catching efficiency, and the diameter of the lateral flange of the gas tree is relatively large Small, it is difficult to hold pressure balls with large diameters, which limits the number of staged fracturing stages

[0006] (2) The settling tube of the vertical sinking ball catcher is easily filled by the flowback proppant and occupies a large amount of ball catching space, reducing the number of balls caught and the efficiency of catching balls

[0007] (3) The spring claw, the core component of the spring claw ball catcher, is continuously impacted and easily deformed and damaged, which reduces the service life and increases the production cost

[0008] (4) The discharge area of ​​the round-hole screen-type ball catcher is small, and the captured pressure-holding balls directly fill up the round holes of the screen pipe, resulting in pressure-holding at the wellhead, resulting in the failure of subsequent pressure-holding balls to be discharged smoothly

[0009] (5) When unloading the captured ball under pressure, it is necessary to close the wellhead and disassemble the ball catcher, resulting in discontinuous ball capture, increasing the working cycle and reducing the ball catching efficiency

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